medical Definition of hydration
1
: the act or process of combining or treating with water: as
a
: the introduction of additional fluid into the body
- hydration sometimes helps to reduce the concentration of toxic substances in the tissues
b
: a chemical reaction in which water takes part with the formation of only one product
- hydration of ethylene to ethyl alcohol
2
: the quality or state of being hydrated;
especially
: the condition of having adequate fluid in the body tissues
